CO_2封存和提高采收率过程中岩石与饱和水的CO_2反应研究  

REACTIVITY OF ROCK IN WATER- SATURATED CO_2 DURING CARBON DIOXIDE STORAGE AND ENHANCED OIL RECOVERY

作　　者：王秀宇[1] 杨胜来[1] 杨永忠[2] 舒梅 王贵刚 

机构地区：[1]中国石油大学石油工程学院 [2]大庆油田有限责任公司第二采油厂井下作业公司 [3]川庆钻探公司钻采工程技术研究院 [4]川庆钻探公司工程技术处

出　　处：《钻采工艺》2015年第3期87-90,14,共4页Drilling & Production Technology

基　　金：国家973项目基金"提高致密油储层采收率机理与研究方法";项目编号:2015CB250904;中国石油大学(北京)引进人才科研启动基金"原油乳状液稳定性的机理研究及其对提高采收率的影响";项目编号:YJRC-2013-30

摘　　要：CO2注入及封存在地层中是减少二氧化碳排放量的有效措施,同时注CO2驱油也是提高原油采收率的重要方法。在地层中的不同位置,水和CO2相互溶解的程度不同。以往的许多研究都集中在矿物与碳酸的反应,而忽视了矿物与溶解了水的超临界CO2的反应。文章通过高温高压实验发现白云石和页岩与无水超临界CO2不反应,而与饱和水超临界CO2反应使部分矿物溶解并重结晶。反应温度和反应时间是影响新形成矿物的组成、形态和反应程度的关键参数。反应形成的矿物溶解和重结晶会改变岩石的润湿性、相对渗透率和毛管压力曲线等,最终影响CO2的注入能力、封存效果和盖层完整性;用CO2进行水气交替提高原油采收率过程中,还会影响到水气注入速度和采油速度等。CO2injection in porous reservoirs is a main method to reduce carbon dioxide footprint and to enhance oil recovery. During carbon dioxide capture and storage and water-alternating- gas flooding for enhanced oil recovery,a full spectrum of mutual CO2– H2 O solubility may occur. Most studies prove that geochemical reaction can happen for rocks with CO2-saturated waters,but ignores the reaction between rock and water- saturated CO2. Based on a series of laboratory experiments,it is observed that common reservoir minerals dolomite and shale do not react with anhydrous supercritical CO2,while they dissolve and produce new mineral precipitates by reaction with water- saturated supercritical CO2. Temperature and reaction time control the composition,morphology,and reaction degree of new minerals. Mineral dissolution and recrystal may affect the rock wettability,the relative permeability and capillary pressure. As a result,the injectivity of a CO2 storage reservoir,the efficacy of physical CO2 trapping and integrity of caprock may be affected. The reaction may also affect the injection rate and production rate during water- alternating- gas.

关 键 词：二氧化碳封存 提高原油采收率 岩石与流体相互作用 超临界二氧化碳 矿物溶解 重结晶 

分 类 号：TE357.4[石油与天然气工程—油气田开发工程]